1. Field of the Invention
The present invention relates to a reconfigurable chair and, more particularly to a reconfigurable chair arranged for ease of operation by an elderly or disabled person, to change configuration to assist a person in sitting and standing, to limit the risk of a person becoming trapped in the operating mechanisms thereof and/or comprising means for sensing an abnormal load condition.
2. Related Background Art
It is known to provide a chair whose configuration may be varied by the operation of one or more actuators, for example to vary the configuration of the chair between an upright position and a reclined position or to tilt the chair forwards to assist a person in standing.
The configuration of this prior art chair is typically adjusted by a user, who controls the operation of the or each actuator via a handset.
However, for the elderly or disabled, being those most likely to employ such a seating arrangement, a handset can prove difficult to manipulate.
It is therefore a first object of the present invention to provide an arrangement which obviates the requirement for a handset to adjust the configuration of a reconfigurable chair.
A further drawback of the prior art chair is that it is often difficult for a person to reseat himself or herself when the chair is in a forwards tilted position and so he or she will be required to operate the handset to return the chair to an upright position before sitting, thereby lengthening the amount of time that the person must remain unseated. As such seats are typically used by elderly or disabled persons, such a delay may easily result in a fall or, collapse and is therefore unsatisfactory.
Furthermore, we have found that it is uncommon for a person to return a forwards tilted seat to an upright position immediately upon standing and thus the seat may remain in a forwards tilted position for some period of time, during which the chair might inadvertently be returned to an upright position by a child, thereby giving rise to the risk of entrapment.
It is therefore a second object of the present invention to provide an arrangement which obviates the requirement for an unseated person to return a reconfigurable chair from tilted position to an upright position.
Sadly, cases have recently been reported of persons being injured through a part of their body becoming trapped in the operating mechanisms of the prior art chair, when the actuators thereof are accidentally operated.
It is therefore a third object of the present invention to provide an arrangement wherein the risk of such entrapment is reduced.
It is also known to provide the prior art chair with means for sensing an abnormal increase in current drawn by the actuator(s) thereof, indicative of an abnormal load condition.
However, where a single actuator is used to adjust, in sequence, the positions of two or more different parts of a chair, the amount of current drawn by the actuator in each stage of adjustment may differ substantially. For example, a single actuator may be arranged adjust the position of the squab and/or back of the chair, therein drawing a current of approximately 5 amps, and, as a separate operation, the position of a footrest, therein drawing a lesser current of approximately 1 amp.
Hitherto, the current sensing means associated with such an actuator arrangement have been arranged to sense when the current drawn by the actuator exceeds a particular value, greater than that which is normally drawn during the adjustment of the squab and/or back of the chair, and thus an abnormal load condition, when adjusting the position of the footrest, will not be detected until the increase in current drawn by the actuator far exceeds a level at which serious damage to the operating mechanism of the footrest may result.
It is therefore a fourth object of the present invention to provide an arrangement wherein an abnormal load maybe sensed in different configurations of a reconfigurable chair.